Gas-air supply system



Aug. 5, 1969 A. E. WAsTlE 3,459,519

- GAS-AIR SUPPLY SYSTEM Filed Jan. 7, 1965 .122 -2-4 I'. ,Z lo 34- INVENTOR BY hmm WMM ATTORNEYS.

United States Patent() 3,459,519 GAS-AIR SUPPLY SYSTEM Arthur E. Wastie, Westfield, NJ., assignor to Drake &

Townsend, Incorporated, New York, N.Y., a corporation of New York Filed Jan. 7, 1965, Ser. No. 424,018 Int. Cl. C10k 3/06; B01f 3/04 U.S. Cl. 48-191 15 Claims ABSTRACT F THE DISCLOSURE A portable, self-contained unit for converting gas from a liquefied petroleum gas storage cylinder to an air-gas mixture having the heating Value of the State standard for city gas. The air for mixing with the liquefied petroleum gas from the storage cylinder is drawn into the gas stream by an aspirator which delivers the gas-air mixture at the pressure required for a domestic appliance which is designal for standard city gas.

This invention relates to systems for supplying gas from a high pressure storage L.P.gas cylinder to a low pressure line; and to gas-air mixers for taking bottled L P. gas at relatively high pressure and supplying it to gas appliances, such as stoves, at the low pressure commonly used in city gas mains.

It is an object of the invention to provide an improved gas-air mixer that converts bottled gas to an equivalent of natural gas at low pressure.

One way in which bottled gas is used is to supply it, through a pressure regulator, to gas appliances such as stoves where it mixes with air on its way to a burner. Such appliances should be designed for the bottled gas, usually propane, and they cannot be used with city gas or natural gas without adjusting for the lower pressure and the lower heating value gas.

With pipe lines and the distribution of natural gas being expanded at such a rapid rate, it is disadvantageous for consumers beyond a distribution area to have to put in appliances with bottled gas burners and then have the expense of converting the appliances for natural gas when the natural gas reaches their distribution area. From the point of view of the natural gas distributor, it is objectionable to have large numbers of families in an area equipped with bottled propane systems and not willing to become natural gas customers, when the gas lines reach their area, because of the cost of the conversion.

It is another object of this invention to provide a selfcontained and portable unit that can be installed in individual homes for supplying bottled gas under conditions that make it suitable for gas appliances that are designed for use with natural gas from domestic distribution lines.

Other objects, features and advantages of the invention will appear to be pointed out as the description proceeds.

In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views:

FIGURE 1 is a diagrammatic front view of a gas-air supply system made in accordance with this invention, the view being partly broken away and in section, and almost all of the front cover being broken away to show the structure behind it.

FIGURES 2 and 3 are sectional views taken on the lines 2-2 and 3 3, respectively, of FIGURE 1;

FIGURE 4 is a diagrammatic section view, on an enlarged scale, through a portion of the aspirator shown in FIGURES 1 and 3, the section being taken on the line 4 4 of FIGURE 3; and

FIGURE 5 is a greatly enlarged detail view taken on the section line 5-5 of FIGURE 1.

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The gas-air supply system shown in the drawing includes a housing 10 having a top wall 12, a bottom wall 14 and side walls 16 and 17. The housing 10 has a double back wall panel 20 which includes a forward panel 22 and a rearward panel 24. The walls 12, 14, 16 and 17 extend all the way to the rearward panel 24 and form, with the panels 22 and 24, a surge tank 26 which is connected in the system in a manner which will be described.

The housing 10 has a sliding front wall 28 with side edges which extend into guide channels 30 at the forward ends of the sidewalls 16 and 17, as clearly shown in FIG- URE 5.

The front Wall 28 contacts with the bottom wall 14 when fully closed, and it has a flange 34 at its upper end which serves as a handle for lifting the front wall 28 to expose the parts located within the housing 10. In the preferred construction, all of the walls of the housing 10 are made of sheet metal. The front wall 28 has sufficient friction in the guides 30, in proportion to its weight, so that it will remain open at any position to which it is moved.

Bottled gas, preferably propane, is supplied from a storage cylinder 40 which is preferably located outside of the housing 10. The gas from the cylinder 40 passes through a valve 42 on the cylinder and through a pressure regulator 44, carried by the cylinder 40, and in which the gas undergoes an initial reduction in pressure. A supply line 46 connects the pressure regulator 44 with a fitting 48 extending through the side wall 16 of the housing 10'. From this fitting 48, the gas flows through a supply line 50 to a second pressure regulator 52. A needle valve 51 regulates the flow of gas through the supply line 50.

The pressure regulator 52, which also includes a filter, is of conventional construction with an adjustment 54 for regulating the excessive pressure, and with a drain 56 which can be opened occasionally to withdraw condensate from the regulator.

A gauge 60 is connected with the gas supply line 50 on the upstream side of the pressure regulator 52. Another gauge 62 is connected with the gas supply line on the downstream side of the pressure regulator 52 by a tube connection 64.

Beyond the tube connection [64, there is a solenoidoperated shut-olf valve 66 in the gas supply line 50. The solenoid or electric motor means for operating the shutoif valve 66 is designated by the reference character 68 and is supplied with power through electrical conductors 69. There is another pressure gauge 70 attached to the gas supply line on the downstream side of the valve 66 by a tube connection 72. Beyond this tube connection 72, the gas supply line leads to an aspirator 74. This aspirator 74 is of conventional construction and includes a nozzle 76 (FIGURE 4) which discharges into the upper end of a venturi passage 78 extending downwardly in the housing 10 to a discharge conduit 80 (FIGURE l) which extends through the forward panel 22 for discharging a gasair mixture from the aspirator into the surge tank formed by the double back wall of the housing 10.

Air is supplied to the aspirator 74 through an air inlet conduit 84. This air inlet conduit 84 contains a check valve 86 (FIGURE 3) for preventing back ow of air or gas from the aspirator 74; and contains also an adjustable butterfly valve 88 for regulating the rate of air flow through the air inlet conduit 84 for any particular suction head. A filter 90 is located at the inlet end of the air inlet conduit 84.

In the illustrated construction, the check valve 86 is of a type which has a valve element 92. that swings about a pivot axis 94 to close the check valve, and the check valve 86 is located on a downwardly sloping portion of the air inlet conduit 84 so that there is a larger component of force of gravity for urging the check valve element 92 into closed position. The butterfly valve 88 contains a valve element 98 adjustable into any desired position by a handle 100. This handle 100 has sufficient friction to hold the butterfly valve in adjusted position, but locking means can be used, if desired.

The inlet end of the air inlet conduit 84, which is covered by the filter 90, opens through the side wall 17 (FIGURE l) and there is no part of the air inlet conduit 84 which communicates with the interior of the housing 10. In the event that the system functions improperly and gas from the aspirator 74 backs up through the air inlet conduit 84, and past the check valve 86, there can be no escape of gas into the interior of the housing 10, with the accompanying hazard which would result. Any such escape of gas from the housing is to the outside atmosphere.

There is an explosion-proof electric junction box 104 attached to the side wall 17 and the electric conduits 69 lead to this junction box 104. A powder supply line 106 connects the explosion-proof junction box 104 with an outside source of electric power.

There is a tube connection 108 communicating with the discharge conduit 80 on the downstream side of the aspirator 74. A pressure gauge 110 is connected with one end of the tube connection 108, and a controller 112 is connected with the tube connection 108 at an intermediate location, as illustrated. This controller 112 is responsive to the pressure in the tube connection 108 and is, therefore, also responsive to the pressure in the discharge conduit with which the tube connection 108 communicates. The controller 112 includes a pressureoperated switch for controlling the supply of electric current to the electric motor means 68 that open and close the valve `66. Such pressure-operated switches are well understood in the art and no illustration of the construction is necessary for a complete understanding of this invention. In a practical application of the invention, the controller 112 may be adjusted so as to open the Valve 66 when the pressure in the tube connection 108 drops to three pounds (gauge) and to again close the valve 66 when `the pressure rises to three and one-half pounds. These values are given merely by way of illustration.

The surge tank 26 (FIGURE 2) has an outlet conduct 116 near its upper end. This outlet conduit 116 contains an adjustable pressure regulator 120 for obtaining a iinal and equal control of the pressure at which the gas-air mixture from the surge tank is delivered to a distribution line or appliance in which the gas is used. The outlet conduit 116 leads to a fitting 122 (FIGURE l) in the Side wall 16. This tting is connected with tubing 124 that leads to the appliance or distribution line.

The unit illustrated in the drawing is portable and can be carried by hand from one location to another. Since it is somewhat bulky, it is .preferably provided with two handles 130 and 132 (FIGURE 2), located at opposite sides of the housing 10, so that the unit can be easily picked up and carried by two persons. In the illustrated construction, the handle 130 is fastened to the top of the surge tank 26 and the handle 132 is attached to the top wall 12 just behind the sliding front wall 28.

When the front wall 28 is in its closed position, the housing 10 is fully closed and all of the equipment in the housing is protected. Whenever it is necessary to have access to any of the structure in the housing 10, the front wall 28 can be opened as much as necessary to gain such access; but when the unit is in normal use, the front wall is closed. If it is desired to have the gauges 60, 62, 70 and 110 (FIGURE 1) exposed when the unit is operating, the front wall 28 need be opened only slightly, as shown in FIGURE 2. To obtain this advantage, al1 of the gauges 60, 62, 70 and 110, which are of substantially less height than the housing 10, are located near the bottom wall 40. The faces of the gauges are located just behind the front 4 wall 70 and the gauges are held in fixed positions by brackets (FIGURE 2) attached to the bottom wall 14.

The preferred embodiment of the invention has been illustrated and described, but changes and modifications can be made and some features can be used in dilferent combinations without departing from the invention as defined in the claims.

What is claimed is:

1. A gas-air supply system including a cylinder in which liqueed petroleum gas is stored under high pressure, a regulator that reduces pressure of gas from the cylinder to a substantially lower, aspirator-operating pressure, a valve for controlling the ow of gas through the regulator, an aspirator downstream from the valve and having a nozzle through which the gas is discharged at standard domestic appliance operating presure, an air supply line connected with the aspirator and through which air is drawn by the aspirator for mixing with the gas, the air supply line being correlated with the nozzle to reduce the heating value of the gas to the State standard for city gas, a discharge conduit through which the mixed air and gas from the aspirator ow to a domestic appliance, and a pressure-responsive controller exposed to the domestic appliance pressure in said discharge conduit for opening and closing the valve that controls flow from the liqueed petroleum gas storage cylinder.

2. The gas-air supply system described in claim 1 characterized by the regulator, valve, air supply line, aspirator, discharge conduit and pressure-responsive controller being connected with a common support and forming a selfcontained portable unit for movement from one location to another Without dismantling said unit.

3. The gas-air supply system described in claim 2 characterized by the support being a housing in which the regulator, valve, air supply line, aspirator, discharge conduit and pressure-responsive controller are enclosed.

4. The gas-air supply system described in claim 3 characterized by the housing having walls, one of which is movable to open the housing on one side for access to the parts enclosed within the housing, and at least one of the walls being hollow and comprising a surge tank which is connected in series with the discharge conduit downstream from the aspirator.

5. A portable, self-contained unit for converting gas from a liquefied petroleum gas storage cylinder to an airgas mixture having a heating value of the State standard for city gas and having the pressure for a domestic gas appliance, including in combination a supply line for connection with a liqueed petroleum gas storage cylinder, a pressure regulator in which gas is reduced in pressure from that of the high pressure storage cylinder to a substantially lower, aspirator-operating pressure, a poweroperated valve for controlling the How of gas through the pressure regulator, an aspirator having a nozzle to which gas is supplied from the regulator, an air inlet line connected with the aspirator and through which air is drawn by the aspirator for mixing with the gas from said nozzle, a discharge conduit for supplying an air-gas mixture having a heating value of the State standard for city gas from the aspiartor to a domestic appliance, the pressure drop through the aspirator being approximately equal to the amount by which the delivery pressure of the regulator exceeds the pressure for operating a domestic appliance, a pressure-responsive controller exposed to the pressure of the mixed gas and air `from the aspirator for supplying power to operate said valve, and a support to which the parts of the mixer assembly are connected to form a portable, self-contained unit.

6. The mixer assembly described in claim 5 characterized by electric motor means operably connected with the valve for moving the valve between open and closed positions, and the pressure-responsive controller including an electric switch in a circuit of said electric motor means.

7. The mixer assembly described in claim 5 characterized by the support including a housing in which parts of the mixer assembly are enclosed, the housing having one wall which is movable to expose the interior of the housing and the parts enclosed therein.

8. The mixer assembly described in claim 7 characterized by the housing having a double wall at one side forming a surge tank for the gas-air mixture, the surge tank being connected in series with the aspirator between said aspirator and the discharge conduit.

9. The mixer assembly described in claim 7 characterized by the valve being in series with the regulator on the discharge side thereof, pressure gauges connected with both the upstream and downstream sides of the regulator, other pressure gauges connected with the downstream side of the Valve and with a gas-air passage downstream of the aspirator, the gauges being Within the housing near the lower end thereof, and the movable wall being slideable upward to expose the gauges during the iirst part of its upward movement.

lil. The mixer assembly described in claim 9 characterized by all of the elements except the ends of the conduits being located within the housing, the movable wall of the housing being the front wall, the housing having side walls with guides on opposite side walls and in which opposite side edges of the front wall slide to raise and lower the side wall, all of the gauges being of substantially less height than the housing and being located in the lower part of the housing and in a row and facing forward immediately behind the front wall when said wall is in closed position whereby the gauges are exposed when the front wall is raised for only a short part of the height of the housing.

11. The mixer assembly described in claim 10 characterized by the back Wall of the housing being a double wall and forming a surge tank for the gas-air mixture and being n series with the aspirator and the discharge conduit.

12. The mixer assembly described in claim 11 characterized by handles secured to the housing at the top of the surge tank and to the top of the housing just behind the front wall for. lifting the assembly when it is to be carried from one location to another.

13. The mixer assembly described in claim 12 characterized by the supply line and the discharge conduit opening through one side wall of the housing, and the air inlet to the aspirator opening through the side wall at the other side of the housing.

14. The mixer assembly described in claim 5 characterized by a check valve in the air inlet line, including a swingable valve element that closes to prevent back flow from the aspirator, the part of the air inlet line that contains the check valve sloping downward and in a direction away from the aspirator when the housing is in its intended operating orientation.

15. The mixer assembly described in claim 5 characterized by parts of the assembly including the aspirator being enclosed within the housing, and the air inlet to the aspirator extending through a Wall of the housing and being closed against any communication with lthe interior of the housing whereby any back ilow of the gas-air mixture from the aspirator vents outside of the housing.

References Cited UNITED STATES PATENTS 2,606,108 8/1952 Ensign 48-191 2,738,261 3/1956 Drake. 3,233,987 2/1966 Hepburn 4s-191XR MORRlS O. WOLK, Primary Examiner R. E. SERWIN, Assistant Examiner us. r11. xn. ism-184; ling-9s 

